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Na 3 V 2 (PO 4) 3 is a promising potential cathode for sodium-ion batteries owning to its stable three-dimensional structure framework. However, from the perspective of environmental protection, the substitution of vanadium with low cost and low toxicity elements is pressing to further boost its application in large-scale energy storage production. To reduce the content of V in Na 3 V 2 (PO 4) 3 and increase the transfer number of sodium ions, ball-milling assisted sol-gel routine is employed to prepare Na 4 FeV(PO 4) 3 @C sodium-rich cathode, which delivers an initial charge capacity high to 175.6 mAh g−1 with high coulombic efficiency of 99% from 1.3 to 4.3 V, deriving from V(II)/V(III), Fe(II)/Fe(III), V(III)/V(IV) and V(IV)/V(V) redox couples. The cathode shows long-life span with an excellent retention of 96.8% after 800 cycles at 5C from 1.8 to 3.8V. Solid-state 23Na nuclear magnetic resonance reveals that the sodium ions at 8-coordinated Na2 sites in Na 4 FeV(PO 4) 3 @C show faster extraction/insertion dynamics during electrochemical cycling. X-ray diffraction and time-of-flight neutron powder diffraction results demonstrate that the electrochemical process undergoes a reversible solid solution reaction with stable structure, resulting in fast rate performance and excellent cyclic retention. The composition modulation of the sodium rich material and the cycling mechanisms obtained from this study would contribute a great insight for the sodium energy storage with improved performances. [Display omitted] • Pure-phase sodium-rich Na 4 FeV(PO 4) 3 materials with carbon coating were prepared by ball-milling assisted sol-gel method with heat-treatment. • The Na 4 FeV(PO 4) 3 @C electrodes deliver an initial charge capacity high to 175.6 mAh g−1 from 1.3 to 4.3 V, deriving from V(II)/V(III), Fe(II)/Fe(III), V(III)/V(IV) and V(IV)/V(V) redox couples, and show excellent retention of 96.8% after 800 cycles at 5C from 1.8 to 3.8V. • The Na 4 FeV(PO 4) 3 @C electrodes undergo a reversible single-phase solid solution reaction with a relatively small variation volume (2.05%) during the charging/discharging process. • The full cell of Na 4 FeV(PO 4) 3 @C//Hard carbon delivers an energy density of 286 Wh kg−1. [ABSTRACT FROM AUTHOR]

• X-ray CT and digital subtraction efficiently reveal internal fluid in coal specimens. • Using fluid information data to characterize effective imbibition pore-fractures. • Imbibition model fits well, surpassing Lucas-Washburn in viscous-inertial stage. • Initial imbibition occurs in smaller pores, shifting to larger ones at equilibrium. • Capillary radius most significantly affects imbibition model sensitivity. Flow and distribution of fluids within coal is of great significance for studying the enhancement of coal seam water injection and permeation-wetting effects, achieving dust pollution control, and gas disaster management. In this regard, relying on the theory of imbibition dynamics, the imbibition model based on microscopic structural parameters is derived. X-ray computed tomography (CT) scanning imaging experiments are conducted on coal in both dry and imbibition-saturated states. Utilizing digital image subtraction technique, pore-fractures structure characteristics and fluid distribution are extracted. A comprehensive investigation is conducted to explore the fluid ascent behavior in individual capillaries and flow characteristics within the pore-fracture networks, thereby revealing the mechanisms through which pore-fractures influence fluid migration during imbibition. The results demonstrate that digital image subtraction technique accurately reveals the fluid distribution within coal. The volume of pore-fractures in different regions is a critical factor influencing fluid distribution, with large fractures playing a major role in maintaining and supporting spontaneous imbibition equilibrium. A microscopic-scale imbibition model based on shape factors and curvature correction is established, and effective pore-fractures are characterized using imbibition fluid data. The established imbibition model exhibits a good overall fit at various imbibition stages, especially during the viscous-inertial stage, where the model significantly outperforms the traditional Lucas-Washburn model. Furthermore, the proportion of effective pore-fractures involved in imbibition is not constrained by the distribution pattern of total pore-fractures. Pore-fractures with equivalent radii ranging from 100 to 500 μm have the highest proportion, serving as the main pathways in the initial stage of imbibition rate increase. The driving force required for the rise of the liquid meniscus inside capillaries is positively correlated with the equivalent radius, making it easier for liquid to ascend in smaller-radius capillaries. Among the various factors influencing imbibition evolution, the imbibition model exhibits the highest sensitivity to capillary radius, demonstrating that capillary structural parameters are crucial factors affecting imbibition. [ABSTRACT FROM AUTHOR]

Due to frequent fire accidents and stone scarcity, fire protection design and recycled aggregates are issues that needed to be solved in the construction industry. Steel tubes and slurry-wrapping reinforcement treatment can effectively improve the load-bearing capacity of recycled concrete. This paper reports on the mechanical behavior of slurry-wrapping recycled aggregate concrete-filled steel tube (CFST) columns after exposure to high temperatures. Three series of 30 CFST columns were designed with the coarse aggregate type and exposure temperature as variation parameters: natural aggregate concrete-filled steel tube (NACFST) column, recycled aggregate concrete-filled steel tube (RACFST) column, and slurry-wrapping recycled aggregate concrete-filled steel tube (SRACFST) column. The results show that the failure pattern of the specimen is less affected by the exposure temperature and the coarse aggregate type. The compressive strength of the RACFST columns is significantly increased after the slurry-wrapping treatment. With the temperature increasing, the ultimate strength tends to increase initially and then drop. Since the recycled concrete has more pores, the compressive strength loss rate of the RACFST columns is lower than that of the NACFST and SRACFST columns at 800 °C. The lateral deformation factor is maintained until the exposure temperature reaches 400 °C and then begins to decrease as the temperature increase. It is not accurate to predict the strength of CFST columns after high temperatures by ultrasonic pulse velocity. The predicted strength of CFST column after high temperatures was compared with design codes, and an equation considering the material strength variation was proposed. • The role of slurry-wrapping reinforcement treatment on CFST columns at high temperatures. • Use ultrasonic pulse velocity to predict the recycled concrete after high temperatures. • An equation considering the material strength variation after high temperatures was proposed. [ABSTRACT FROM AUTHOR]

Abstract As high penetration of uncertain wind and solar energy into power system, spatio-temporal correlation of wind and solar energy is of great necessity for planning and operation of wind farms and PV plants. A Copula function and first order Markov process based Monte Carlo simulation method of multivariate wind speed and PV power spatio-temporal series is proposed in this paper. In the proposed approach, either spatial correlation or temporal correlation of wind speed and PV power series is considered including cross-correlation between all series and self-correlation of every series. The results of case study based on National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy are analyzed, which verify the scientific and feasibility of the proposed approach. [ABSTRACT FROM AUTHOR]

• Crystal field splitting and dressing induced splitting coexist in 5D J -7F J transitions of Eu3+ ions. • Compare Stark splitting and dressing effect in different crystal phases of BiPO 4 micro-crystals. • The time-resolved excitation spectra of Eu3+-doped BiPO 4 at different delay time and excitation conditions. • The photon–phonon nested dressing theory is employed to explain the line-shape evolution. The Stark splitting of 5D J -7F J transitions has been investigated by time-resolved dressing excitation spectra in Eu3+-doped BiPO 4 micro-crystals with different phase structures. The evolution of the Stark transition peaks significantly depends on the laser power, bandwidth, delay time, temperature, and phase structures of BiPO 4 crystals. It is explained by photon-phonon coupling dressing effect. There is competition between the crystal field splitting and the dressing splitting alignment in the line-shape evolution. The time-resolved dressing excitation spectrum provides an effective method to investigate Stark splitting and modulate line-shape for applications in optical communication. [ABSTRACT FROM AUTHOR]

Abstract: The near-stoichiometric LiNbO3 (SLN) single crystals doped Mn2+, Co2+ and Ni2+ in 0.5mol% concentration in the raw compositions were grown by the Bridgman method under the conditions of taking K2O as flux, a high temperature gradient (90–100°C/cm) for solid–liquid interface. The XRD, absorption spectra, excitation spectra and emission spectra have been carried out. From the absorption edges of Mn2+, Co2+ and Ni2+-doped SLN crystals, the molar ratio of [Li+]/[Nb5+] are estimated to be about 0.977. The absorption spectra of Mn2+:SLN have shown a broad absorption band centered at ∼571nm (6A1g(6S)→ 4T1g(4G)), three absorption peaks at 520, 549 and 612nm (overlapping of the 4T1(F)–4A2(F), 4T1(F)–4T1(P)), and a wide absorption band at 1400nm (4T1(F)→ 4T2(F)) of Co2+:SLN, Ni2+:SLN, and five absorption peaks at 381nm (3A2g(F)→ 3T1g(P)), 733nm (3A2g(F)→ 3T1g(F)), 1280nm (3A2g(F)→ 3T2g(F)), 430nm (3A2g(F)→ 1T2g(D)), and 840nm (3A2g(F)→ 1E(D)) of Ni2+:SLN were observed. A red emission at 612nm (4T1g(4G)→ 6A1g(6S)) for Mn2+:SLN, a red emission at 775nm (4T1(P)→ 4T1(F)) for Co2+:SLN, and a green emission at 577nm (1T2g(D)→ 3A2g(F)) and a red emission at 820nm (1T2g(D)→ 3T2g(F)) for Ni2+:SLN were observed under excited by 416, 520 and 550nm lights, respectively. The concentration distribution of Mn2+, Co2+and Ni2+ ion in SLN crystals was investigated primarily from the absorption and emission spectra for various parts. The effective distribution coefficient for Mn2+ was less than 1. While, for Co2+ and Ni2+ were more than 1. [Copyright &y& Elsevier]

The growth of Fe doped LiNbO3 single crystals by the Bridgman method had been reported. Large-size, 0.04 mol% Fe2O3 containing single crystals with good optical property were obtained under the optimum conditions: choosing proper raw materials, sealed platinum crucibles and convex or plane solid–liquid interface with a temperature gradient around 20–30 °C/cm, at the growth rate of 1–3 mm/h. X-ray diffraction (XRD) and differential thermal analysis (DTA) were used to characterize the single crystals. The UV–Visible spectra of lower and upper parts of the single crystals were measured and the Li and Fe concentrations in the crystals were analyzed by using inductively coupled plasma (ICP) spectrometry. The results indicated that the overall Fe and Fe2+ concentration in the single crystal slightly increased from lower to upper parts. The addition of small amount of Fe ions induced bigger lattice parameters. [Copyright &y& Elsevier]

The growth of LiNbO3 crystals by the modified Bridgman method has been reported. The feed material with accurate congruent melt composition is suitable to grow the crystals. Composition change of the melt during growth can be avoided by sealing platinum crucibles. Using the optimum conditions such as growth rate of 1–3 mm/h and temperature gradient around 30°C/cm across the solid–liquid interface, the congruent LiNbO3 crystals without macro-defects have been grown successfully. [Copyright &y& Elsevier]

The growth of novel birefringent crystal α-BaB2O4 by the modified Bridgman method has been reported in this paper. By means of the optimum conditions such as stoichiometric feed materials, sealed platinum crucibles, [001] growth direction, growth rate less than 0.3 mm/h and convex or plane solid–liquid interface with temperature gradient 30–40 °C/cm, large-size crystals without macro-defects have been grown successfully. [Copyright &y& Elsevier]

To reveal the influence of CFB slag on the mechanical and expansion properties of self-compacting recycled aggregate concrete (SCRAC), five SCRACs with different CFB slag replacement amounts were made, the cubic compressive strength test, the splitting tensile strength test, the axial compressive strength test, and the dry shrinkage test were carried out. The failure processes and failure forms of SCRAC under compression and tension were observed. The effects of the influence of the CFB slag replacement rate on the basic mechanical properties of SCRAC were analyzed. The conversion relationship between various mechanical indicators of SCRACs was explored. The drying shrinkage performance of SCRAC was tested using the grey theory. The test results indicate that the compressive failure of SCRAC using CFB slag as fine aggregate is similar to that of SCC. The results show that the cubic compressive strength, splitting tensile strength, and axial compressive strength of self-compacting recycled concrete are the highest when the sand replacement ratio of CFB slag is 10%. The proposed conversion relationship between the cubic compressive strength of SCRAC and other mechanical properties indexes has high accuracy. GM (1, N) model and grey correlation analysis were established to analyze the influencing factors of drying shrinkage of SCRAC. The drying shrinkage deformation of SCRAC using CFB slag as fine aggregate has a hyperbola relationship with time, and a lower CFB slag sand replacement rate can compensate for the shrinkage of SCRAC. • The influence of CFB slag on the mechanical of self compacting recycled aggregate concrete(SCRAC). • The influence of CFB slag on the expansion properties of SCRAC. • The proposed conversion relationship of SCRAC. • Establishe GM(1, N) model and grey correlation analysis. • 5.Analyze the influencing factors of drying shrinkage of SCRAC. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-line effectively improves the capture efficiency of the bacteria. • Trace amount of PDA NPs could be identified by Image J. • PDA NPs-based multi-line LFIAs of E. coli with the visual LOD of 102 CFU/mL. • PDA NPs-based multi-line LFIAs achieved a gray value LOD of 2.8 CFU/mL for E. coli detection. Lateral flow immunoassay strips (LFIAs) are a reliable and point-of-care detection method for rapid monitoring of bacteria, but their sensitivity was limited by the low extinction coefficient of colloidal gold nanoparticles (Au NPs) and low capture efficiency of test-line. In this study, polydopamine nanoparticles (PDA NPs) were employed to replace Au NPs, due to their high extinction coefficient. And the amount of test-line was increased to 5 for further improving the efficiency of bacteria capture. Thus, under visual observation, the detection limits of PDA-based LFIAs (102 CFU/mL) were about 2 orders of magnitude lower than Au-based LFIAs (104 CFU/mL). Furthermore, the invisible signal could be collected by Image J and the detection limit can reach 10 CFU/mL. The proposed test strips were successfully applied for the quantitative, accurate, and rapid screening of E. coli in food samples. This study provided a universal approach to enhance the sensitivity of bacteria LFIAs. [ABSTRACT FROM AUTHOR]

The growth of LiNbO3 single crystal doped with Eu3+ ions by the Bridgman method and the characteristics of temperature-dependent emission spectra were reported. By means of the optimized conditions such as proper raw materials, sealed platinum crucibles, growth rate of 1–3 mm h−1 and convex or plane solid–liquid interface with a temperature gradient around 20–30 °C cm−1, large size crystals containing 0.1 mol% Eu3+ ion with good optical quality were obtained. X-ray diffraction and DTA were used to characterize the crystals. The temperature-dependence emission spectra of lower and upper part of crystals from 77 to 600 K were investigated under the excitation of a 488 nm light. The results show that, for the upper part of crystal, the fluorescence intensity of Eu3+ ions increased with increasing the temperature as a whole. However, for the lower part, it first increased with increasing the temperature, and then decreased obviously with increasing the temperature. The variations of fluorescence intensity for the lower and upper parts of crystals were discussed. The decrease of emission intensity was induced by the temperature-quenching effect. [Copyright &y& Elsevier]

Eu2O3 was incorporated into Na2O–TeO2–ZnO glasses by a melting method in air atmosphere. The fluorescence, excitation spectra of the glasses, was studied. The results indicate that some of the europium ions in the glass exist in state of divalent although they were prepared at air atmosphere. The IR spectra of the glasses were measured. The structural and compositional effects on the state of europium ions were discussed. [Copyright &y& Elsevier]

[Display omitted] • Triethylamine-responsive QDs based on supramolecular self-assembly was synthesized. • Fluorescence of QD621/ZnS/HPEISA increased greatly after adding triethylamine. • QD621/ZnS/HPEISA supramolecular self-assembly was cleaved by excess triethylamine. • Released QDs/HPEI nanocomposites could easily be endocytosed by the L929 cells. A new strategy for the construction, release and cellular imaging application of triethylamine-responsive fluorescent quantum dots (QDs) based on supramolecular self-assembly has been described. The supramolecular self-assembly (HPEI/SA), which was constructed through the electrostatic interactions between terminal amine groups of hyperbranched polyethylenimines (HPEI) and carboxylic acid groups of stearic acid (SA), first captured aqueous Zn2+ ions into the hydrophilic dendritic core and subsequently encapsulated QDs/S2- by the complexation interactions and reactions between Zn2+ and S2- on QDs. Due to the pH-responsive property of the HPEI/SA supramolecular self-assembly, the fluorescence of encapsulated QDs is sensitive to the triethylamine/SA mole ratio, and the encapsulated QDs can be released to the aqueous phase by cleaving HPEI/SA. The resulting fluorescent QDs/HPEI nanocomposites show promising prospects in bioimaging. [ABSTRACT FROM AUTHOR]

• Nonviral gene vector with folate/magnetism targeting based on hyperbranched polymer. • FA-PEG-HPEI as nanoreactors to prepare superparamagnetic Fe 3 O 4 nanocrystals. • Fe 3 O 4 /FA-PEG-HPEI have higher luciferase expression level than HPEI. A new strategy for in situ preparation of non-viral gene vectors with folate/magnetism dual targeting based on hyperbranched polymers has been described. Folate-PEG-grafted-hyperbranched poly(ethylenimine)s (FA-PEG-HPEI) were synthesized and used as nanoreactors to prepare monodisperse Fe 3 O 4 nanocrystals (NCs). The FA-PEG-HPEI had FA targeting groups, low cytotoxicity and ideal gene transfection performance, while Fe 3 O 4 NCs had superparamagnetic property, thus the resulting Fe 3 O 4 /FA-PEG-HPEI nanocomposites integrated the properties of FA-PEG-HPEI and Fe 3 O 4 NCs together. As expected, the Fe 3 O 4 /FA-PEG-HPEI nanocomposites as non-viral gene vectors with folate/magnetism dual targeting had improved luciferase expression level in HEK 293T and Hela cells under a magnetic gradient field. The luciferase expression level mediated by Fe 3 O 4 /FA-PEG-HPEI nanocomposites in HEK 293T and Hela cells under a magnetic gradient field were 21 and 29 fold of that of standard HPEI transfection, respectively. [ABSTRACT FROM AUTHOR]